Ethics of Emerging Technologies: Geoengineering

geoengineering: The application of large-scale engineering methods to modify rock formations or other features of the natural environment;esp. (in later use) the modification of the global environment or the climate in order to counter or ameliorate climate change. (From the Oxford English Dictionary)

The University of Oxford's Centre for Practical Ethics has put out a short paper entitled "The Ethics of Geoengineering", which is a good summary of some of the issues at stake.

See also the Univerity of Montana's extensive online resource on geoengineering.